近红外光谱法田间快速估测新鲜紫花苜蓿品质

田间快速估测苜蓿品质对于适时刈割具有重要意义。试验共采集来自不同地域、不同品种、不同生育期和不同茬次的新鲜紫花苜蓿样170份，经便携式近红外光谱仪(1 100～1 800 nm)扫描得到近红外光谱，利用偏最小二乘法(PLS)在国内首次建立基于紫花苜蓿新鲜样品的干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)化学分析值的近红外校正模型，探讨利用近红外漫反射光谱技术(NIRS)在田间快速估测紫花苜蓿品质的可行性，摸索设备选择和制样方法。四项指标所建模型的交互验证决定系数(R2CV)分别为0.831 4，0.597 9，0.803 6和0.786 1;交互验证均方根误差(RMSECV)为1.241 1，0.261 4，0.990 3和0.830 6;外部验证决定系数(R2_V)为0.815 0，0.401 1，0.784 9和0.752 1，外部预测均方根误差(RMSEP)分别为1.06, 0.31, 0.95和0.80。对于苜蓿鲜样来说，DM，NDF和ADF的近红外模型可以进行粗略的定量分析，CP的建模效果较差，但因苜蓿中的粗蛋白含量一般都能满足家畜需求，DM，NDF和ADF是在适时刈割中最关键的估测指标，DM，NDF和ADF模型可以满足田间快速估测苜蓿品质的要求。

Alfalfa Quality Evaluation in the Field by Near-Infrared Reflectance Spectroscopy

To explore the feasibility of using near-infrared reflectance spectroscopy(NIRS) to evaluate alfalfa quality rapidly in the field and try to find the appropriate machine and sample preparation method, the representative population of 170 fresh alfalfa samples collected from different regions with different stages and different cuts were scanned by a portable NIRS spectrometer (1 100～1 800 nm). This is the first time to build models of fresh alfalfa to rapidly estimate quality in the field for harvesting in time. The calibrations of dry matter(DM), crude protein(CP), neutral detergent fiber(NDF) and acid detergent fiber (ADF)were developed through the partial least squares regression(PLS). The determination coefficients of cross-validation (R2CV) were 0.831 4, 0.597 9, 0.803 6, 0.786 1 for DM, CP, NDF, ADF, respectively; the root mean standard error of cross-validation(RMSECV) were 1.241 1, 0.261 4, 0.990 3, 0.830 6; The determination coefficients of validation (R2_V) were 0.815 0, 0.401 1, 0.784 9, 0.752 1 and the root mean standard errors of validation(RMSEP)were 1.06, 0.31, 0.95, 0.80 for DM, CP, NDF, ADF, respectively. For fresh alfalfa ,the calibration of DM, NDF, ADF can do rough quantitative analysis but the CP’s calibration is failed. however, as CP in alfalfa hay is enough for animal and the DM, NDF and ADF is the crucial indicator for evaluating havest time, the model of DM, NDF and ADF can be used for evaluating the alfalfa quality rapidly in the field.